Arthur Eric Magana (PCSO photo)

Closing arguments began in Arthur Magaña’s murder trial Monday afternoon in Pinal County Superior Court, and the jury began deliberation within an hour.

Magaña, 18, is accused of killing 20-year-old Wyatt Miller by shooting him 11 times inside his truck on Nov. 7, 2016.

The alleged murder took place in a rural area of Maricopa during the theft of four ounces of marijuana, according to court testimony. Magaña was just 16 years old at the time of the murder but is charged as an adult due to the gruesome nature of the murder.

Magaña’s murder and armed robbery trial began Wednesday and was handed to the nine-woman, three-man jury Monday afternoon just after 2 p.m.

State opened closing arguments.

“What is the value of a life,” said prosecutor Patrick Johnson. “For this defendant, life is cheap. It was just the cost of doing business.”

Gustavo Olivo was also involved in the crime and has already pleaded guilty to charges of second-degree murder and armed robbery.

“He (Magaña) fired 11 rounds into the back of his head, and Wyatt didn’t even see it coming. He took the cowards way out and never gave him a chance,” Johnson said in closing arguments.

Officers trained in tracking followed footprints to a house where the defendants were located, according to Johnson.

“They made it pretty easy for them… They led officers right to themselves,” Johnson told the jury.

Investigators smelled marijuana after entering the house and found the four ounces of marijuana, allegedly taken from Miller. More evidence was found in the freezer and their shoes matched the prints. Blood was also found on their shoes, according to Johnson.

“This isn’t a self-defense case,” Johnson said. “This is not a case where someone has no other choice but to use lethal force.”

Johnson said the 9mm semi-automatic HK handgun used in the murder was purchased by Magaña’s mother. He added that blood on Magana’s clothing matched Miller’s DNA.

“He never realized he had Wyatt Miller’s blood on him,” Johnson told the jury.

Johnson called the crime a planned armed robbery and execution.

“His body tells you what happened. Of the 11 wounds, not one was in the face. Wyatt Miller never saw it coming,” Johnson said.

Johnson said Magana also bragged about the murder and “was proud of what he did. He was the one who pulled the trigger 11 times and killed Wyatt Miller… Not only killed him he executed him…it was a cowardly execution.”

Defense attorney David Gregan reviewed the “proof beyond a reasonable doubt” statute with the jury. He said Olivo and Miller knew each other, and that Olivo is the one who went around the vehicle and grabbed the marijuana after the alleged murder took place.

“The state wants to convince you that this was a planned robbery,” Gregan said. “But that’s not the case.”

He said it wasn’t a planned robbery because they didn’t take everything and didn’t have a plan of escape from the scene.

“The evidence you saw at trial dictated that something happened out there,” Gregan said.

Gregan told the jury to realize Magaña was just 16 years old at the time and was defending himself.

“Something happened out there before the shooting. What it was, we do not know… no one knows for sure,” Gregan said.

Gregan said there was a second 9mm gun inside the vehicle that was not tested by investigators. The untested gun raised uncertainty, according to Gregan.

During the State’s rebuttal, Johnson said, “We know exactly what happened before the shooting because he (Magaña) told us… He executed him by shooting him in the back of the head 11 times.”

Johnson said the two made posts on Facebook before the incident indicating this was a planned armed robbery and Magaña bragged about the murder on videotape while in custody.

Johnson called Magaña the mastermind behind the armed robbery and execution and that Miller’s life had value and meaning even if he was a drug dealer.

“Wyatt Miller’s life had more value than four ounces of marijuana,” said Johnson.

Judge Kevin D. White read jury instructions and sent the jury to begin deliberations on the two charges, first-degree murder and armed robbery.